In a typical distribution system of signals in a content delivery network, such as for cable or satellite television, there are various components that reside on a single physical system or on separate systems linked by one or more communication networks. Such content delivery networks may include content providers which provide content delivered across the network, such as audio, video, data, applications, or combinations thereof.
In a content delivery network, the content is typically provided by content providers into the content delivery network as one or more signals. Such signals are typically encoded to prevent unauthorized access and use of the signal. Receivers, such as digital television receiver units, receive from the network and use such encoded signals for use by users. A receiver typically includes a decode function so that receivers may make use of the encoded signals it receives from the content delivery network. A content delivery network also typically includes a conditional access system connected to the network, which controls the content that any particular receiver may access and use. The conditional access system typically operates in conjunction with the receivers to control the content that any one receiver may access and use. A receiver typically perform checks with the conditional access system to determine the particular content that it is permitted to receive and use, and then decode only such authorized content.
The content delivery network will also typically contain other systems such as subscriber management systems for maintaining and billing customer subscriptions, pay-per-view, video-on-demand, interactive television and other systems which may in turn have records or subsystems used for controlling access to services, features or content, which may be directly or indirectly related to the conditional access system.
Access to various services available on the network is typically controlled through authorizations entered into the subscriber management system. Individual subsystems may in turn have records relating to individual receiver service authorizations. Such records of authorization may in one form or another be duplicated on various systems, and each system may independently exert control over access to the related service or signal.
Furthermore, a conditional access system or and other systems with service or signal authorization records may not necessarily provide facilities for a large number of content providers to enter authorizations or to manage billing and other customer-oriented functions. Likewise, conditional access systems known in the art may not provide interfaces or functions for the handling of large volumes of transactions except through a connection to a subscriber management system. Where such facilities may be provided within a conditional access system, network operators may not be accustomed to using them, as they may not provide convenient or easily usable interfaces, and they may not include logging and other audit trail mechanisms.
Additional background details regarding content delivery networks, conditional access systems, and technologies deployed therein are described in various U.S. patents.
4,461,032to Skerlos4,510,623to Bonneau et al.5,146,496to Westerfer et al.5,224,161to Daniel et al.5,880,769to Nemirofsky et al.5,970,206to Yuen et al.6,067,440to Diefes5,485,518to Hunter et al.5,828,402to Collings5,438,620to Ryan et al.
Some conditional access systems known in the art have been compromised in a manner that allows for unauthorized usage of content signals. Methods of compromising these systems include deliberate or accidental operational errors, exploitation of design or operational flaws in the systems, and “hacking” or reverse-engineering of the systems.
Detection of unauthorized access and usage may often be rendered difficult, as a compromised receiver may not have a method of communicating back with the conditional access system, or the return communication means may be disabled on the compromised receiver.
Correction of conditional access problems may also be a lengthy process, with compromised (also known as “pirated”) systems sometimes remaining in operation for several years, with a succession of counter-measures and counter-counter-measures being deployed respectively by the content delivery network operators and hackers.
Operational errors, software or hardware problems or other sources of errors may cause discrepancies to occur between subscriber management systems, conditional access systems and other systems such as video-on-demand servers. In such a cases, it may be possible for a receiver to access a service or signal which the network operator does not intend to authorize for that receiver.
There is a need for a system and method for identifying and reconciling differences within various authorization systems to control unauthorized access to signals and services.